Unimpressed with debit order department service

Good day I need assistance I have phoned the debit order department for assistance but they seem too *********** to assist me or give me information. I approved a debit order mandate and the company has not lived up to it promise and I phoned last month and gave the information to the debit order department and they said it would cost R80 to stop it it was not stopped and that money got taken off and I want that money back what do I do. I phoned again just now to *** and spoke to Ernest who said that FNB dont cancel debit order mandates but refused to give me any further assistance in regards to resolving my issue. I asked twice do I need to open a ***** case to get that mandate stopped and just reiterated that FNB cant stop mandates. I have been banking with FNB for years now and this is what I get for the service fees I pay its *******